LLY: Danville 72-R 4094 VS Duramaxtuner Stealth 67.7

dirtymax36

2nd place is last
Apr 11, 2013
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Anyone out there running a stealth 67.7? Checking out on one of these. I currently have the 72R with 71mm turbine tuned by kory and I can't seem to keep coolant temp down when towing. New mishimoto radiator, pump, stats, and hoses. Normal driving it's 179* all day until hooked to a trailer towing it'll get to 225 easily even though EGTs are under 850*. To me it seems like the truck is under load 100% and is struggling to pull a trailer worse than my friends stock Lmm. Many shops have told me it's because of drive pressure and tuning. Whats everyone think about switching from the 72R to the DT67.7? basically it's a drop in ready to rock s467.7/83/.8ar. Hoping to make it tow better and still make 800wrhp. Any thoughts and ideas would be appreciated, I tow 14k-20k regularly and need every bit of help I can get. High coolant Temps in the 230 range aren't doing the trick. I'm also open to trying different tuning and hard parts. Thanks in advance
 

Frankin_truck

Member
Nov 22, 2013
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I towed a bit with that exact charger your talking about the stealth 67.7. It did a great job towing, my set was a bit different. Was running it twined over a s484 with 100 over's. Spooled great and egt''s and coolant temp were normal
 

dirtymax36

2nd place is last
Apr 11, 2013
367
2
18
Seems like I have all the right cooling system parts but I haven't seen anone else with this issue, and how did the 67.7 do as a single ?

Also this charger is for sale currently for $2500 with 1900 miles on it and I would be open to trading for a 67.7 or s400 kit
 

dirtymax36

2nd place is last
Apr 11, 2013
367
2
18
Btw forgot to say my tow tune is around 650hp as far as I know. Thought about trying a baby 500hp tune even though it might be a little laggy.

Also the truck has dual flexalite fans on a manual switch which I keep on 24/7 when truck is running, and the intercooler and radiator are brand new along with my 12AN external oil cooler up front I fabricated.

I can try a mechanical fan again but I don't have a clutch laying around anymore. Trying to keep as much stress off the front drive as possible for crank's sake
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Btw forgot to say my tow tune is around 650hp as far as I know. Thought about trying a baby 500hp tune even though it might be a little laggy.

Also the truck has dual flexalite fans on a manual switch which I keep on 24/7 when truck is running, and the intercooler and radiator are brand new along with my 12AN external oil cooler up front I fabricated.

I can try a mechanical fan again but I don't have a clutch laying around anymore. Trying to keep as much stress off the front drive as possible for crank's sake

put one on. bet it runs cooler. buy this clutch, it will come on sooner and help with temps some as well as make the a/c work a bit better since the delay for the fan to come on isnt as long.

https://www.amazon.com/gp/product/B002PL5PBG/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

EDIT: be sure to run the fan shroud and the caged circular shroud, that piece will make a difference in cooling.
 

dirtymax36

2nd place is last
Apr 11, 2013
367
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The only thing I don't like about the electric fans is the bottom 5 inches of the radiator isn't covered by the fan shroud it pulls air through.

Is that part number the lower temp clutch? I was wanting to stay away from a fan clutch, I gained around 1.2 mpg and some throttle response when I made the switch over
 

clrussell

pro-procrastinator
Sep 23, 2013
5,905
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Put a mechanical fan and proper shrouds on it or quit bitching about towing coolant temps.

There isn't a pair of electric fans im aware of that flow anywhere near as much air as the stock fan set up.


You shouldn't be towing on a tune anywhere near 650 with a single and no fan.
 

dirtymax36

2nd place is last
Apr 11, 2013
367
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This never has been a problem since this year, all other years towing with a Danville 72vgt and same engine set up had the same issue. I ran a fan clutch last 2 years and electric fans this year, it ran better with electric fans and cooler with electric fans versus the clutch style. Egts are also very low
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,108
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Phoenix Az
The only thing I don't like about the electric fans is the bottom 5 inches of the radiator isn't covered by the fan shroud it pulls air through.

Is that part number the lower temp clutch? I was wanting to stay away from a fan clutch, I gained around 1.2 mpg and some throttle response when I made the switch over

yes that is the lower temp operating clutch

you have 5" of radiator that is getting 0 air pulled across it. it strictly relies on outside air which is very turbulent and not exactly guiding its self into the radiator. on top of that, you are using fans that do not pull the same amount of CFM a stock fan can pull.

put a fuel cooler on and the mechanical fan back in and the 1.2mpg you gained will stay the same when you tow.

your only other option is this

http://secondarycoolingsystems.bigcartel.com/product/auxiliary-radiator
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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This never has been a problem since this year, all other years towing with a Danville 72vgt and same engine set up had the same issue. I ran a fan clutch last 2 years and electric fans this year, it ran better with electric fans and cooler with electric fans versus the clutch style. Egts are also very low

see the pattern?
 

Awenta

Active member
Sep 28, 2014
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CT
Every day driving sure it was cooler. But towing not a chance. Especially not that heavy. Above 8k electric fans just aren't going to cut it.

Sent from my SM-N910V using Tapatalk
 

dirtymax36

2nd place is last
Apr 11, 2013
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Meaning of when i put the 72R On. Not trying to sound like a smartass but I will try this mechanical fan and we can see how it goes, I tried this fan before with a 68mm fleece cheetah on a stock motor and had this issue
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Meaning of when i put the 72R On. Not trying to sound like a smartass but I will try this mechanical fan and we can see how it goes, I tried this fan before with a 68mm fleece cheetah on a stock motor and had this issue

make sure you run both the cage that goes behind the fan and the shroud.

the mechanical at the VERY LEAST will allow you to go far farther up the hill before temps reach 230. your right foot with a single 72, 60% overs and 650hp tune is pushing things very hard.
 

Awenta

Active member
Sep 28, 2014
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20k pounds and 650hp. Turbo isn't going to change much.

James^ does the same thing. Listen to him.

Sent from my SM-N910V using Tapatalk
 

dirtymax36

2nd place is last
Apr 11, 2013
367
2
18
Hayden Fan clutch on order. I will report findings this upcoming weekend, do you all use locktite on the fan clutch nut or leave it?

Also, i just had kory pull a lot of fuel out of my tow tune to get it into the 400hp range.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,108
4,843
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Phoenix Az
Hayden Fan clutch on order. I will report findings this upcoming weekend, do you all use locktite on the fan clutch nut or leave it?

Also, i just had kory pull a lot of fuel out of my tow tune to get it into the 400hp range.

i would suggest you change/try one thing at a time so you know what exactly fixed it but if those two changes dont keep it from instantly getting hot, you have hard part issues